The conventional method for measuring the barrier properties of films consists of placing a film sample between two chambers containing a test gas of interest in a first chamber and a carrier gas in the second chamber. As the test gas permeates through the film sample it is collected in the second chamber and subsequently measured by an appropriate detector.
Factors which contribute to the measurement value are often referenced and include film thickness, temperature, relative humidity, and other specifics of the test gas mixture, such as ratios of other gases present.
Testing should typically be conducted at various temperatures and relative humidity to ascertain the effect each of these factors has upon permeability of the film.
Accordingly, a need exists for a cost effective system and method capable of generating test gases of known relative humidity with the ability to quickly, simply and accurately adjust the relative humidity of the test gas between 0% and 100%.